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A265395
Record values in A265388.
4
0, 6, 15, 33, 91, 435, 703, 1891, 2701, 12403, 18721, 38503, 49141, 79003, 88831, 104653, 146611, 188191, 218791, 226801, 269011, 286903, 385003, 497503, 597871, 665281, 721801, 736291, 765703, 873181, 954271, 1056331, 1314631, 1373653, 1537381, 1755001, 1869211, 1987021, 2035153, 2284453, 2741311, 3059101, 3270403, 3363121, 3913003
OFFSET
1,2
COMMENTS
Question: Are all terms apart from 0 and 435 (= 3*5*29) semiprimes? See also comments in A265394 & A265396.
LINKS
FORMULA
a(n) = A265388(A265394(n)).
PROG
(PARI) lista(nn) = {r = 0; for (n=1, nn, nr = gcd(vector(n-1, k, binomial(2*n, 2*k))); if (nr > r, print1(nr, ", "); r = nr); ); } \\ Michel Marcus, Dec 08 2015. Note: this gives correct value for a(1) only from PARI version 2.8 onward, see A265388 for why. - Antti Karttunen, Dec 11 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 08 2015
STATUS
approved